In the engagement and intercept of a hostile ballistic missile (BM), a weapon system will typically track the ballistic missile objects using a ground-based radio frequency (RF) sensor and transmit track information to an intercepting missile for processing. The intercepting missile is typically equipped with an infrared (IR) sensor which is used to acquire and track the hostile ballistic missile objects as part of the engagement sequence.
Hostile ballistic missiles, however, can be expected to deploy decoy objects to conceal the warhead(s) and avoid tracking and interception. Multiple objects from one or more BM launch events may therefore be present in the IR sensor field of view (FOV). In order to select and guide to the targeted object, a correlation process takes place in order to relate the RF track information to the IR track information. However, uncertainties in both the RF and IR tracks, due at least in part to measurement noise and systematic errors can lead to degraded correlation performance. In addition, for certain intercept geometries, the objects observed by the IR sensor may appear close together in angle and be separated by unknown distances in range. Objects closely spaced within the IR sensor FOV relative to the magnitude of their uncertainties results in diminished resolvability. This brings about degraded correlation performance. The accuracy of the correlation process is important to the success of the intercept. Furthermore, determination of the object of interest drives missile guidance algorithms to complete the intercept. Cases where the object of interest is incorrectly determined may result in extremely degraded intercept performance.
In many cases, objects may be separated by significant distances in missile-to-object range. However, due to the “angles-only” nature of the IR sensor measurements, missile-to-object range is not directly available.
Prior art implementations of BM engagement systems rely on object separation within the IR sensor FOV to be above an identified threshold and do not account for missile-to-object range in their correlation processing. For cases with objects spaced closely in angle with respect to the IR sensor focal plane, complications may result.
Alternative systems and methods are desired.